In agent_receive_reply we first call the callback for the pending
request (agent_finalize_pending) then try to send the next request
in the queue. Check that the next request has not been sent already
which could happen if it has been just queued by the callback.
The difference in the handlers was that in the
NETDEV_EVENT_DISCONNECT_BY_AP case we would make sure to reply
to a pending dbus Connect call. We also need to do that for
NETDEV_EVENT_DISCONNECT_BY_SME. This happens if another process
sends an nl80211 disconnect command while we're connecting.
The eapol handshake timeout can now be configured in main.conf
(/etc/iwd/main.conf) using the key eapol_handshake_timeout. This
allows the user to configure a long timeout if debugging.
After an EAP exchange rsn_info would be uninitialized and in the FT case
we'd use it to generate the step 2 IEs which would cause an RSNE
mismatch during FT handshake.
Until now we'd save the second 32 bytes of the MSK as the PMK and use
that for the PMK-R0 as well as the PMKID calculation. The PMKID
actually uses the first 32 bytes of the PMK while the PMK-R0's XXKey
input maps to the second 32 bytes. Add a pmk_len parameter to
handshake_state_set_pmk to handle that. Update the eapol_eap_results_cb
802.11 quotes to the 2016 version.
handshake_state_install_ptk triggers a call to
netdev_set_pairwise_key_cb which calls netdev_connect_ok, so don't call
netdev_connect_ok after handshake_state_install_ptk. This doesn't fix
any specific problem though.
If the request being cancelled by agent_request_cancel has already been
sent over dbus we need to reset pending_id, the timeout, call l_dbus_cancel
to avoid the agent_receive_reply callback (and crash) and perhaps start
the next request. Alternatively we could only reset the callback and not
free the request, then wait until the agent method to return before starting
the next request.
Move the cancelling of the eapol timeout from the end of step 1 to
step 3 to guard the whole handshake. At the end of step 1 stop the
EAPOL-Start timeout for the case of 802.1X authentication + a cached
PMKSA (not used yet.)
Some APs respond to Neighbor Report Requests with neighbor reports that
have a zero operating class value and a non-zero channel number. This
does not mean that the channel is in the same band that the reporting
AP operates in. Try to guess the band that the channel refers to out of
2.4 and 5GHz -- the bands supported by those APs.
wpa_supplicant also has this workaround in place.
SA Query procedure is used when an unprotected disassociate frame
is received (with frame protection enabled). There are two code
paths that can occur when this disassociate frame is received:
1. Send out SA Query and receive a response from the AP within a
timeout. This means that the disassociate frame was not sent
from the AP and can be ignored.
2. Send out SA Query and receive no response. In this case it is
assumed that the AP went down ungracefully and is now back up.
Since frame protection is enabled, you must re-associate with
the AP.
1. Enforce implementation of handle_request function
2. In case of unimplemented handle_retransmit try to use
handle_request instead and rely on method specific
mechanism to restart the conversation if necessary
3. Make method->free implementation unrequired
When we call scan_periodic_stop and a periodic scan is in progress (i.e.
the trigger callback has been called already) we get no new callback
from scan.c and the device Scanning property remains True forever so set
it to False.
The change from scan_periodic_stop to periodic_scan_stop looks silly but
it's consistent with our naming :)
This patch adds a watcher/parser for the frame event associated with
an AP directed BSS transition (AP roaming). When the AP sends a BSS
transition request, this will parse out the BSS candidate list
(neighbor report) and initiate a roam scan. After this point the
existing roaming code path is reused.
The identity retrieved from simauth was required to include the
prefix for SIM/AKA/AKA', but in reality a real SIM would not
include that prefix in the IMSI. Now the correct prefix is
prepended onto the identity depending on the EAP method.
If the SQN in AUTN is incorrect the simauth module will return
the AUTS parameter, which is sent back to the server and the
servers SQN number is updated.
Forcing a plugin to create and register simauth at once is sometimes
inconvenient. This patch separates the creation and registration
into two API's, and also adds several others to add the required simauth
data incrementally (identity, driver data, sim/aka support). This also
allows for the driver to unregister the auth provider without freeing
up the simauth object itself e.g. if the driver temporarily becomes
unavailable, but will come back sometime in the future.
The simauth watch API's were also renamed. Watchers will now get a
callback when the provider has been unregistered, so they have been
renamed to sim_auth_unregistered_watch_[add|remove].
src/simauth.c:163:6: error: no previous declaration for ‘sim_auth_cancel_request’ [-Werror=missing-declarations]
void sim_auth_cancel_request(struct iwd_sim_auth *auth, int id)
^~~~~~~~~~~~~~~~~~~~~~~
iwd now supports plugin loading, whitelisting and blacklisting. Both
the whitelist and the blacklist support multiple patterns separated by a
',' character.
Make sure device->autoconnect is set when entering the autoconnect state
after netdev UP event. Otherwise the next time
device_set_autoconnect(device, false) is called it will exit early seeing
that device->autoconnect is false and not switch the device state.
This is the core module that takes care of registering
authentication drivers. EAP-SIM/AKA will be able to acquire
a driver that supports the required algorithms. The driver
implementation (hardcoded/ofono etc.) is isolated into
separate plugin modules.
EAP-SIM/AKA/AKA' retrieve the EAP-Identity off the SIM card
not from the settings file. This adds a new EAP method API
which can optionally be implemented to retrieve the identity.
If get_identity is implemented, the EAP layer will use it to
retrieve the identity rather than looking in the settings file.
network_settings_load expects NULL value to be returned
on failed attempts to read the settings files inside of
storage_network_open. At the same time storage_network_open
used to always return an initialized l_settings
structure despite the outcome of the read operations,
indicating a success.
When the 4-Way Handshake is done eapol.c calls netdev_set_tk, then
optionally netdev_set_gtk and netdev_set_igtk. To support the no group
key option send the final SET STATION enabling the controlled port
inside the callback for the netdev_set_tk operation which always means
the end of a 4-Way Handshake rather than in the netdev_set_gtk callback.
The spec says exactly that the controlled port is enabled at the end of
the 4-Way Handshake.
The netlink operations will still be queued in the same order because
the netdev_set_tk/netdev_set_gtk/netdev_set_igtk calls happen in one
main loop iteration but even if the order changed it wouldn't matter.
On failure of any of the three operations netdev_setting_keys_failed
gets called and the remaining operations are cancelled.
Track the contents and size of the GTK and IGTK and if the Authenticator
(or an adversary) tries to set the same GTK/IGTK, process the packet
normally but do not resubmit the GTK/IGTK to the kernel.
GTK KDE was being checked for being a minimum of 6 bytes. Not quite
sure why since the minimum GTK key length is 16 bytes for CCMP.
Similarly make sure that the maximum length is not more than 32, which
is currently the largest key size (TKIP)
This is a bizarre case since MIC calculation succeeded for the incoming
packet. But just in case MIC calculation fails for the outgoing packet,
kill the handshake.
The comments quoted sections of the specification that indicated STA
behavior for verifying Message 3 of 4 or GTK 1 of 2. But in reality the
code directly below simply calculated the MIC for Message 4 of 4 or GTK
2 of 2.
Use eapol_frame_watch_add/eapol_frame_watch_remove in eapol_sm, while
there simplify the early_frame logic and confirm sender address for
received frames.
Set all the new field values into struct sta_state only after all the
error checks for better readabilty and fixing a possible issue if we
did "sta->rates = rates" and then detected en error and freed "rates".
Also update a comment which I think used the wording from 802.11-2012
instead of 802.11-2016.
DEL_KEY is not needed and will return errors right after NEW_STATION or
right after DEL_STATION. In both cases the kernel makes sure there are
no old keys for the station already.
As a temporary DBus API to switch between Station and Access Point
modes, add two methods on the Device interface. Add a new state
DEVICE_STATE_ACCESS_POINT which is in effect from the moment
StartAccessPoint is received (even before it returns) until
StopAccessPoint returns, there are no intermediate states when the
methods run for simplicity. Add checks across device.c to make sure
Station related functionality is disabled when in Access Point mode.
Add a utility to append a KDE to the key_data field in an EAPoL frame.
The KDE types enum is actually added to handshake.h because we've got
the utilities for finding those KDEs in a buffer there. The new
function is specific to EAPoL-Key frames though and perhaps to simple to
be split across handshake.c and eapol.c. Also it didn't seem useful to
use the ie_tlv_builder here.
Parse Association Request frames and send Association Responses, handle
Disassociation. With this we should be able to receive uncontrolled
port data frames since we register the STAs with the kernel.
In this version I don't register for Reassociation frames.
Validate the IE order for some of the cases. For other cases, as with
the Disassociation, Deauthentication and Action frame types in section
9.3 it's not even clear from the spec the fields are expected to be IEs
(in fact for Action frame we know they aren't). For the Shared Key
authentication type drop the union with the contents as they can be
easier parsed as an IE sequence. For SAE we are not expecting an IE
sequence apparently so this is where the union could come useful but
let's leave that until we want to support SAE.
Check the IE order for each frame type where we'd just do the body
minimum length check until now (and not always correctly). We do not
try to validate the contents of any IEs (may be doable for some) or the
minimum mandatory IEs presence. This is because which IEs are required
depend on the contents of other fields in the frame, on the
authentication state and STA config and even contents of a request frame
which we're validating the response to. Frame handlers have to do this
work anyway.
Declare the two missing frame subtype enum values for Action frames,
assume Action frames are valid. Once we have specific validation code
for any Action frames elsewhere, we can move it to mpdu_validate, but
right don't try to validate the frame body as there are many subtypes
and we don't use any of them except Neighbor Reports which are actually
really simple.
Since we use the special 0xffff value in the builder code, check that
the tag is not 0xffff in ie_tlv_builder_finalize before writing the
header. This is for consistency, not for a specific use case.
Make parsing TLVs using Extended Element IDs easier by returning the
extended tag value as listed in enum ie_type instead of just the 255
value, and not returning the pointer to the extended tag as the IE data
and instead the pointer to the next byte after the extended ID.
The l_queue_find() to find other watches matching the new prefix
needs to be before the watchlist_link(), otherwise the prefix will
match itself and "registered" is always true.
In WATCHLIST_NOTIFY_MATCHES pass pointer to the item instead of
item->notify_data to free item->notify_data to be the final watch user's
user_data. This is also what netdev expects.
The EAP-method's .probe methods only checked the method name so do that
in eap.c instead and allocate method state in .load_settings. Rename
method's .remove method to .free to improve the naming.
This can be used to selectively notify watchlist items. The match
function is called for each watchlist_item and match_data is passed
along. If the match function returns true, then the watch_item is
notified. The match function signature and semantics are identical
to l_queue_match_func_t.
Rename netdev_register_frame to netdev_frame_watch_add and expose to be
usable outside of netdev.c, add netdev_frame_watch_remove also. Update
the Neighbor Report handling which was the only user of
netdev_register_frame.
The handler is now simpler because we use a lookup list with all the
prefixes and individual frame handlers only see the frames matching the
right prefix. This is also useful for the future Access-Point mode.
src/mpdu.c: In function ‘mpdu_validate’:
src/mpdu.c:180:9: error: ‘mmpdu’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
mmpdu = (const struct mmpdu_header *) mmpdu;
^
Refactor management frame structures to take into account optional
presence of some parts of the header:
* drop the single structure for management header and body since
the body offset is variable.
* add mmpdu_get_body to locate the start of frame body.
* drop the union of different management frame type bodies.
* prefix names specific to management frames with "mmpdu" instead
of "mpdu" including any enums based on 802.11-2012 section 8.4.
* move the FC field to the mmpdu_header structure.
This EAP method uses nearly all the logic from EAP-AKA. The major
difference is it uses the new key derivation functions for AKA' as
well as the SHA256 MAC calculation.
EAP-AKA' uses SHA256 rather than SHA1 to generate the packet MAC's.
This updates the derive MAC API to take the EAP method type and
correctly use the right SHA variant to derive the MAC.
This is the core key generation code for the AKA' method which
follows RFC 5448. Two new functions are implemented, one for
deriving CK'/IK' and the other for deriving the encryption keys
using CK'/IK'.
If the kernel device driver or the kernel nl80211 version doesn't
support the new RSSI threshold list CQM monitoring, implement similar
logic in iwd with periodic polling. This is only active when an RSSI
agent is registered to receive the events. I tested this with the same
testRSSIAgent autotests that tests the driver-side rssi monitoring
except with all timeouts multiplied by ~20.
The AT_VERSION_LIST attribute length was not being properly
checked. The actual length check did not include possible padding
bytes, so align_len() was added to ensure it was padded properly.
The comment about the padding being included in the Master Key
generation was not correct (padding is NOT included), and was removed.
Function to allow netdev.c to explicitly tell eapol.c whether to expect
EAP / 4-Way handshake. This is to potentially make the code more
descriptive, until now we'd look at sm->handshake->ptk_complete to see
if a new PTK was needed.
A 4-Way handshake is required on association to an AP except after FT.
Modify netdev_get_iftype, which was until now unused, and add
netdev_set_iftype. Don't skip interfaces with types other than STATION
on startup, instead reset the type to STATION in device.c.
netdev_get_iftype is modified to use our own interface type enum to
avoid forcing users to include "nl80211.h".
Note that setting an interface UP and DOWN wouldn't generally reset the
iftype to STATION. Another process may still change the type while iwd
is running and iwd would not detect this as it would detect another
interface setting interface DOWN, not sure how far we want to go in
monitoring all of the properties this way.
If we're adding the BSS to the list only because it is the current BSS,
set the rank to 0 (lowest possible value) in case the list gets used in
the next Connect call.
Allow attempts to connect to a new AP using the Reassociation frame even
if netdev->operational is false. This is needed if we want to continue
an ongoing roam attempt after the original connection broke and will be
needed when we start using cached PMKSAs in the future.
Use beacon loss event to trigger a roam attempt in addition to the RSSI
monitoring. Due to the how well beacons are normally received compared
to data packets, a beacon loss indicates a serious problem with the
connection so act as soon as a first beacon loss event is seen.
Avoid roaming methods that involve the current AP: preauthentication,
neighbor report request and FT-over-the-DS (not supported)
There are situations including after beacon loss and during FT where the
cfg80211 will detect we're now disconnected (in some cases will send a
Deauthenticate frame too) and generate this event, or the driver may do
this. For example in ieee80211_report_disconnect in net/mac80211/mlme.c
will (through cfg80211) generate a CMD_DEAUTHENTICATE followed by a
CMD_DISCONNECT.
The kernel doesn't reset the netdev's state to disconnected when it
sends us a beacon loss event so we can't either unless we automatically
send a disconnect command to the kernel.
It seems the handling of beacon loss depends on the driver. For example
in mac80211 only after N beacon loss events (default 7) a probe request is
sent to the AP and a deauthenticate packet is sent if no probe reply is
receiver within T (default 500ms).
If an application initiates the Connect() operation and
that application has an agent registered, then that
application's agent will be called. Otherwise, the default
agent is called.
==40686== Syscall param sendmsg(msg.msg_iov[0]) points to uninitialised byte(s)
==40686== at 0x5147037: sendmsg (in /usr/lib64/libc-2.24.so)
==40686== by 0x43957C: operate_cipher (cipher.c:354)
==40686== by 0x439C18: l_cipher_decrypt (cipher.c:415)
==40686== by 0x40FAB8: arc4_skip (crypto.c:181)
Initialize the skip buffer to 0s. This isn't strictly necessary, but
hides the above valgrind warning.
The aim of arc4 skip is simply to seed some data into the RC4 cipher so
it makes it harder for the attacker to decrypt. This 'initialization'
doesn't really care what data is fed.
CMD_DEAUTHENTICATE is not available for FullMAC based cards. We already
use CMD_CONNECT in the non-FT cases, which works on all cards. However,
for some reason we kept using CMD_DEAUTHENTICATE instead of CMD_DISCONNECT.
For FT (error) cases, keep using CMD_DEAUTHENTICATE.
Certain WiFi drivers do not support using CMD_SET_STATION (e.g.
mwifiex). It is not completely clear how such drivers handle the
AUTHORIZED state, but they don't seem to take it into account. So for
such drivers, ignore the -ENOTSUPP error return from CMD_SET_STATION.
These flags are documented in RFC2863 and kernel's
Documentation/networking/operstates.txt. Operstate doesn't have any
siginificant effect on normal connectivity or on our autotests because
it is not used by the kernel except in some rare cases but it is
supposed to affect some userspace daemons that watch for RTM_NEWLINK
events, so I believe we *should* set them according to this
documentation. Changes:
* There's no point setting link_mode or operstate of the netdev when
we're bringing the admin state DOWN as that overrides operstate.
* Instead of numerical values for link_mode use the if.h defines.
* Set IF_OPER_UP when association succeeds also in the Fast Transition
case. The driver will have set carrier off and then on so the
operstate should be IF_OPER_DORMANT at this point and needs to be
reset to UP.
Allow registering and unregistering agent object to receive RSSI level
notifications. The methods are similar to the ones related to the
password agent, including a Release method for the agent.
Add an methods and an event using the new
NL80211_EXT_FEATURE_CQM_RSSI_LIST kernel feature to request RSSI
monitoring with notifications only when RSSI moves from one of the N
intervals requested to another.
device.c will call netdev_set_rssi_report_levels to request
NETDEV_EVENT_RSSI_LEVEL_NOTIFY events every time the RSSI level changes,
level meaning one of the intervals delimited by the threshold values
passed as argument. Inside the event handler it can call
netdev_get_rssi_level to read the new level.
There's no fallback to periodic polling implemented in this patch for
the case of older kernels and/or the driver not supporting
NL80211_EXT_FEATURE_CQM_RSSI_LIST.
==27901== Conditional jump or move depends on uninitialised value(s)
==27901== at 0x41157A: handshake_util_find_pmkid_kde
(handshake.c:537)
==27901== by 0x40E03A: eapol_handle_ptk_1_of_4 (eapol.c:852)
==27901== by 0x40F3CD: eapol_key_handle (eapol.c:1417)
==27901== by 0x40F955: eapol_rx_packet (eapol.c:1607)
==27901== by 0x410321: __eapol_rx_packet (eapol.c:1915)
Agent implementation inside agent.c takes a reference of the trigger
message associated with the request. When the callback is called, the
message is passed as an argument. The callback is responsible for
taking the message reference if necessary. Once the callback returns,
agent releases its reference.
For error paths, our code was using dbus_pending_reply which in turn
uses dbus_message_unref. This caused the agent to try an unref
operation on an already freed object.
Move the calling of the *_shutdown functions from the signal handler to
a new public function, and use that function inside the DBus disconnect
handler to make sure resources are cleanly released.
Skip the matching of the PMKID KDE to the PMKID list in the RSNE if
we've seen a new EAP authentication before the step 1/4 was received.
That would mean that the server had not accepted the PMKIDs we submitted
and we performed a new 8021X authentication, producing a new PMKSA which
won't be on the list in the RSNE.
Currently we'd send EAPOL-Start whenever EAP was configured and we
received an EAPOL-Key before EAP negotiation. Instead only do that if
we know we can't respond to the 4-Way handshake because we don't have
a PMK yet or the PMKID doesn't match. Require a PMKID in step 1/4 if
we'd sent a list of PMKIDs in our RSNE.
Modify the packet filter to also accept frames with ethertype of 0x88c7
and pass the ethertype value to __eapol_rx_packet so it can filter out
the frames where this value doesn't match the sm->preauth flag.
Add a wrapper for eapol_start that sets the sm->preauth flag and sends
the EAPOL-Start frame immediately to skip the timeout since we know
that the supplicant has to initiate the authentication.
Use netdev_reassociate if FT is not available. device_select_akm_suite
is only moved up in the file and the reused code from device_connect is
moved to a separate function.
